The French Riviera scenery from this month’s Cannes Film Festival may act as an enticement, but onlookers are advised not to imitate the drastic measures taken in “The Love Punch,” a good-natured if strenuously wacky caper comedy about a divorced British couple who plot a diamond heist to save their pensions.

Because the scheme takes them to Paris and then to Cannes and its surroundings, the ex-spouses, Kate (Emma Thompson) and Richard (Pierce Brosnan), slowly rekindle the spark. After a hedge fund manager (Laurent Lafitte), based in France, strips Richard’s company of its value, Kate agrees to accompany her former husband to Paris, where the two will demand their money back.

When that fails, what else can they do but rob a $10.8 million jewel from the villain’s fiancée (Louise Bourgoin)? A fellow couple (Timothy Spall and Celia Imrie) aid them in this endeavor, which involves kidnapping and impersonating wealthy Texans. As justification, Kate rails against financial fat cats; still, down to its rote soundtrack selections (“All Right Now,” “Takin’ Care of Business”), the film feels too complacent to embody a true fight-the-man spirit.

As in ’60s confections like “Topkapi” — a filmmaking tradition “The Love Punch” self-consciously emulates — some wonderful actors add class to the material, which struggles to find a consistent register of cartoonishness. (The quartet’s wedding-crash-by-snorkel-and-cliff-climb might have impressed James Bond.) The antics bear little resemblance to those that follow actual divorce and financial ruin, any more than “The Love Punch” resembles the films that compete at Cannes.